mount.smbfs tells correct quota-space of remote disk, mount.cifs tells wrong space:

# mount | grep 192
//192.168.105.1/xxx on /mnt/backup type cifs (rw,mand)
//192.168.105.1/xxx on /mnt/backup1 type smbfs (0)

# df | grep -A 1 192
//192.168.105.1/xxx
                     1152359220 501261216 592561564  46% /mnt/backup
//192.168.105.1/xxx
                       73400320  36775936  36624384  51% /mnt/backup1



# cat /proc/fs/cifs/DebugData 
Display Internal CIFS Data Structures for Debugging
---------------------------------------------------
CIFS Version 1.50
Active VFS Requests: 0
Servers:
1) Name: 192.168.105.1  Domain: R-KOM BACKUP Mounts: 1 OS: Unix  
        NOS: Samba 3.0.28       Capability: 0x80f3fd
        SMB session status: 1   TCP status: 1
        Local Users To Server: 1 SecMode: 0x3 Req On Wire: 0
MIDs:

Shares:
1) \\192.168.105.1\xxx Uses: 1 Type: NTFS DevInfo: 0x0 Attributes: 0x2b
PathComponentMax: 255 Status: 1 type: 0